Approximate date of commencement of proposed sale to public: as soon as practicable after this Registration Statement is declared effective.

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. o

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier registration statement for the same offering. o

If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier registration statement for the same offering. o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definitions of "large accelerated filer," "accelerated filer," and "smaller reporting company" in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer o

Accelerated filer o

Non-accelerated filer ý(Do not check if a smaller reporting company)

Smaller reporting company o

CALCULATION OF REGISTRATION FEE

Title of Each Class ofSecurities To Be Registered

Proposed MaximumAggregateOffering Price(1)

Amount ofRegistration Fee(2)

Common Stock, $0.001 par value per share

$175,000,000

$6,878

This is going to be all over the internet, we'll have more next week. Here's the S-1.HT: Cleantech:

The battery maker files to raise up to $175 million in an initial public offering.

Watertown, Mass.-based A123 Systems, which makes advanced lithium-ion batteries and battery systems for the transportation, electric grid and portable power markets, announced today that it plans to raise up to $175 million in an initial public offering.

The company has not yet set the number of shares or a price range, but expects to trade on the Nasdaq under the symbol "AONE."

The news of the filing comes amid a rocky time for the auto industry, which is retooling for smaller, more efficient cars after a drop in sales of larger, gas-guzzling SUVs and light trucks.

A123 Systems has already inked deals that could put its batteries in electric and hybrid vehicles from Norway's Think Global and Detroit's General Motors (NYSE: GM) (see GM, A123Systems to co-develop battery).

The planned share sale also follows a development milestone from a potential competitor in the energy storage market. Last month, Cedar Park, Texas-based ultracapacitor developer EEStor announced the enhancement of its chemical purification processes (see EEStor's Weir on ultracapacitor milestone)....